docs: def _getNextArticleBatch(self):
          """download next batch of events based on the event uris in the uri list"""
          eventUri = self.queryParams["eventUri"]
          # move to the next page to download
          self._articlePage += 1
          # if we have already obtained all pages, then exit
          if self._totalPages != None and self._articlePage > self._totalPages:
              return
          if self._er._verboseOutput:
              print("Downloading article page %d from event %s" % (self._articlePage, eventUri))
  
          self.setRequestedResult(RequestEventArticles(
              page = self._articlePage,
              sortBy = self._articlesSortBy, sortByAsc = self._articlesSortByAsc,
              returnInfo = self._returnInfo,
              **self.queryParams))
          res = self._er.execQuery(self)
          if "error" in res:
              print(res["error"])
          else:
              self._totalPages = res.get(eventUri, {}).get("articles", {}).get("pages", 0)
          arts = res.get(eventUri, {}).get("articles", {}).get("results", [])
          self._articleList.extend(arts)